CN112224190B - Brake boosting system, brake method and electric automobile - Google Patents

Brake boosting system, brake method and electric automobile Download PDF

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Publication number
CN112224190B
CN112224190B CN201910581690.7A CN201910581690A CN112224190B CN 112224190 B CN112224190 B CN 112224190B CN 201910581690 A CN201910581690 A CN 201910581690A CN 112224190 B CN112224190 B CN 112224190B
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China
Prior art keywords
motor
brake
torque
braking
master cylinder
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CN201910581690.7A
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Chinese (zh)
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CN112224190A (en
Inventor
刘峰宇
应卓凡
刘晓康
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Huawei Technologies Co Ltd
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Huawei Technologies Co Ltd
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Priority to CN201910581690.7A priority Critical patent/CN112224190B/en
Application filed by Huawei Technologies Co Ltd filed Critical Huawei Technologies Co Ltd
Priority to PCT/CN2020/079771 priority patent/WO2021000601A1/en
Priority to BR112021010535A priority patent/BR112021010535A2/en
Priority to MX2021006676A priority patent/MX2021006676A/en
Priority to KR1020217013822A priority patent/KR102585991B1/en
Priority to EP20834110.7A priority patent/EP3851348A4/en
Priority to JP2021527947A priority patent/JP7187695B2/en
Publication of CN112224190A publication Critical patent/CN112224190A/en
Priority to US17/339,543 priority patent/US11400816B2/en
Application granted granted Critical
Publication of CN112224190B publication Critical patent/CN112224190B/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L7/00—Electrodynamic brake systems for vehicles in general
    • B60L7/24—Electrodynamic brake systems for vehicles in general with additional mechanical or electromagnetic braking
    • B60L7/26—Controlling the braking effect
    • B—PERFORMING OPERATIONS; TRANSPORTING
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    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
    • B60T13/74—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with electrical assistance or drive
    • B60T13/746—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with electrical assistance or drive and mechanical transmission of the braking action
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    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
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    • B60T13/745—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with electrical assistance or drive acting on a hydraulic system, e.g. a master cylinder
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    • B60T17/00—Component parts, details, or accessories of power brake systems not covered by groups B60T8/00, B60T13/00 or B60T15/00, or presenting other characteristic features
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    • B—PERFORMING OPERATIONS; TRANSPORTING
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    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T7/00—Brake-action initiating means
    • B60T7/02—Brake-action initiating means for personal initiation
    • B60T7/04—Brake-action initiating means for personal initiation foot actuated
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    • F16H1/28—Toothed gearings for conveying rotary motion with gears having orbital motion
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H19/00—Gearings comprising essentially only toothed gears or friction members and not capable of conveying indefinitely-continuing rotary motion
    • F16H19/02—Gearings comprising essentially only toothed gears or friction members and not capable of conveying indefinitely-continuing rotary motion for interconverting rotary or oscillating motion and reciprocating motion
    • F16H19/04—Gearings comprising essentially only toothed gears or friction members and not capable of conveying indefinitely-continuing rotary motion for interconverting rotary or oscillating motion and reciprocating motion comprising a rack
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/60—Other road transportation technologies with climate change mitigation effect
    • Y02T10/70—Energy storage systems for electromobility, e.g. batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/60—Other road transportation technologies with climate change mitigation effect
    • Y02T10/72—Electric energy management in electromobility

Abstract

The application provides a braking helping hand system and braking method, electric automobile, this braking helping hand system includes: brake pedal, helping hand motor, simulation motor, planet row coupling node and brake master cylinder. The brake master cylinder is used for providing braking force of an automobile; the brake pedal, the booster motor and the simulation motor are respectively connected with a planet row coupling node, and the planet row coupling node is used for converting the torque of the brake pedal, the torque output by the booster motor and the simulation motor into acting force acting on a piston rod in the brake master cylinder. From the above description, it can be seen that the output torques of the analog motor and the booster motor are simultaneously used as the force for driving the piston rod of the brake master cylinder by the arranged planet row coupling node, so that the output power requirement of a single motor can be improved. In addition, when the two motors are adopted to drive the brake master cylinder simultaneously, when one motor fails, the other motor can be used for braking, and the reliability of the whole brake power assisting system is improved.

Description

Brake boosting system, brake method and electric automobile
Technical Field
The application relates to the technical field of automobiles, in particular to a brake boosting system, a brake method and an electric automobile.
Background
The new energy automobile is a vehicle type which is developed rapidly at present, and a braking system in the new energy automobile has some differences from the existing gasoline energy automobile due to the adoption of motor driving. As shown in fig. 1, in the brake system of the new energy automobile, when a driver steps on a brake pedal, automobile braking is transmitted through two paths, 1) braking force generated when the driver steps on the brake pedal is transmitted to a hydraulic brake system through a brake boosting mechanism, and a brake master cylinder, a hydraulic pipeline and a brake caliper in the hydraulic brake system apply the braking force to wheels; 2) The motor brake is controlled by the controller, and a driving motor in the motor brake generates reverse torque and directly acts on wheels through a transmission part to realize the brake.
As shown in fig. 2, fig. 2 shows a prior art brake device, which is composed of a brake pedal 1, an actuating motor 2 and an actuating motor 3 in series. The brake pedal 1 is connected with an execution motor 2, and the execution motor 3 is connected with a brake master cylinder 4. The intermediate shafts of the execution motor 2 and the execution motor 3 are not in direct contact and have a gap 5. Therefore, in normal operation, the two execution motors move independently, the execution motor 2 simulates the resistance of the brake pedal 1, and the execution motor 3 pushes the brake master cylinder 4 to build the pressure of hydraulic brake. Thus, the system achieves decoupling between the pedal 1 and the master cylinder 4. In addition, when the actuating motor 2 fails, the brake pedal 1 can still directly push the brake master cylinder 4 through the gap 5 between the two actuating motors, and hydraulic braking force with certain strength is generated. However, the two actuating motors are connected end to end, the length of the system is long, and requirements on space arrangement and installation size are high. In addition, the execution motor 2 is always used as resistance to simulate pedal force, the brake master cylinder 4 can only be pushed by the execution motor 3, and requirements on power, torque and the like of the driving motor 3 are high.
Disclosure of Invention
The application provides a brake boosting system, a brake method and an electric automobile, which are used for improving the brake boosting system of a motor.
In a first aspect, a brake boosting system is provided, which is applied to brake in an electric vehicle driven by a motor. This braking helping hand system includes: brake pedal, helping hand motor, simulation motor, planet row coupling node and brake master cylinder. The brake master cylinder is used for providing braking force of an automobile; the brake pedal, the boosting motor and the simulation motor are used as input mechanisms of braking force, and the planet row coupling nodes are used for driving the brake cylinder to work by the force generated by the input mechanisms. When the brake pedal, the booster motor and the simulation motor are connected with the planet row coupling node respectively, and the planet row coupling node is used for converting the torque of the brake pedal, the torque output by the booster motor and the simulation motor into acting force acting on the piston rod in the brake master cylinder. From the above description, it can be seen that the output torques of the analog motor and the booster motor are simultaneously used as the force for driving the piston rod of the brake master cylinder by the arranged planet row coupling node, so that the output power requirement of a single motor can be improved. In addition, when the two motors are adopted to drive the brake master cylinder simultaneously, when one motor fails, the other motor can be used for braking, and the reliability of the whole brake power assisting system is improved.
In a specific possible embodiment, the planet row coupling node comprises: the device comprises a planetary gear mechanism, a first transmission mechanism, a second transmission mechanism and a third transmission mechanism; the brake pedal drives the gear ring of the planetary gear mechanism to rotate through the first transmission mechanism; the power-assisted motor drives a planet carrier of the planetary gear mechanism to rotate through the second transmission mechanism; the simulation motor is connected with a sun gear of the planetary gear mechanism and is used for driving the sun gear to rotate; the planet carrier pushes the piston rod to move linearly through the third transmission mechanism. Through the cooperation of the planetary gear mechanism and the three transmission mechanisms, the output of the brake pedal, the booster motor and the simulation motor is applied to the brake master cylinder. The decoupling of the brake pedal and the brake master cylinder can be realized by adopting the planet gear mechanism, namely the brake pedal can realize that the brake master cylinder can have different braking forces at the same position, and the brake master cylinder can be adjusted as required at the moment, so that the electro-hydraulic decoupling is realized.
In a specific embodiment, the first transmission mechanism includes a first rack connected to the brake pedal, and a first gear engaged with the first rack, wherein the first gear is fixedly connected to and coaxially disposed with the ring gear. The force of the brake pedal is transmitted to the planetary gear mechanism by adopting the matching of the first gear and the first rack.
In a specific embodiment, the second transmission mechanism includes a worm connected to the booster motor, and a worm wheel engaged with the worm, and the worm wheel is fixedly connected to and coaxially disposed with the carrier. The torque output by the power-assisted motor is applied to the brake master cylinder through a second transmission mechanism consisting of a worm wheel and a worm.
In a specific possible embodiment, the second transmission mechanism comprises a first bevel gear connected with the booster motor and a second bevel gear fixedly connected with the planet carrier, and the first bevel gear and the second bevel gear are meshed. The torque of the booster motor is applied to the brake master cylinder by using the bevel gear set.
In a specific possible embodiment, the third transmission structure includes a second rack fixedly connected to the piston rod of the master cylinder, and a second gear engaged with the second rack, wherein the second gear is fixedly connected to the carrier and is coaxially disposed. The torque of the planetary gear mechanism is converted into linear motion for pushing a piston rod of the brake master cylinder through the matching of the arranged second rack and the second gear.
In a specific possible embodiment, the planet row coupling node further comprises a limiting device for limiting the rotation of the sun gear to a set angle. The planet row coupling node avoids the supporting force for the sun gear provided by the limiting device after the simulation motor fails.
In a specific possible embodiment, the planet row coupling node further comprises a return spring for urging the sun gear to return to an initial position. The sun wheel is pushed to return to the initial position by the arranged return spring.
In a specific possible embodiment, the brake boosting system further includes: the first detection device is used for detecting the braking information of the electric automobile; second detection means for detecting a battery amount of a battery of the electric vehicle; the control device is used for acquiring the braking demand of the electric automobile according to the braking information of the electric automobile detected by the first detection device, and determining the braking force distribution ratio of the motor of the electric automobile and the brake master cylinder according to the braking demand of the electric automobile and the battery quantity of the battery of the electric automobile acquired by the second detection device; acquiring a first torque of the simulation motor according to the acquired braking information of the electric automobile; and determining a second torque of the power-assisted motor according to the first torque of the simulation motor and the braking force distribution proportion of the brake master cylinder, and controlling the power-assisted motor and the simulation motor to output the first torque and the second torque respectively. The decoupling of the brake pedal and the brake master cylinder can be realized by adopting the planet gear mechanism, namely the brake pedal can realize that the brake master cylinder can have different braking forces at the same position, and the brake master cylinder can be adjusted as required at the moment, so that the electro-hydraulic decoupling is realized. Meanwhile, after the brake pedal is decoupled from the brake master cylinder, the control device can select an active brake mode or an assisted brake mode according to the driving state of the electric automobile.
In a specific embodiment, the first detecting device is a first displacement sensor for detecting the position of the brake pedal or an ADAS system of the electric vehicle; and when the first detection device is the first displacement sensor, the braking information of the electric automobile is the position of the brake pedal.
In a specific embodiment, the control device is specifically configured to obtain the braking demand of the electric vehicle according to the position of the brake pedal detected by the first displacement sensor and the set correspondence relationship between the position of the brake pedal and the braking demand. And judging the braking requirement of the electric automobile according to the acquired position of the brake pedal.
In a specific possible embodiment, the control device is further configured to: and acquiring the rotation angle of the sun gear according to the position of the brake pedal detected by the first displacement sensor and the braking force distribution proportion of the brake master cylinder, and acquiring the torque of the return spring to the sun gear according to the rotation angle of the sun gear and the elastic coefficient of the return spring. The push of the return spring to the brake master cylinder is also considered in the braking scheme, so that the control precision is improved.
In a specific implementation manner, the control device is further configured to obtain the braking force of the brake pedal according to the position of the brake pedal detected by the first displacement sensor and the corresponding relationship between the position of the brake pedal and the braking force of the brake pedal; the control device acquires a first torque of the simulation motor according to the acquired braking information of the electric automobile, and the first torque accords with the following formula:
T b_trg ＝i 1 F padel
Figure GDA0003893334470000031
wherein, T m_cmd A represents a gear ratio of the ring gear to the sun gear for the first torque; t is s For the return spring to be opposite to the leafTorque of the male gear, T b_trg Is the torque of the brake pedal, F padel As the braking force of the brake pedal, i 1 The speed ratio coefficient of a first gear and a first rack in the first transmission mechanism is shown.
In a specific embodiment, the control device determines the second torque of the booster motor according to the first torque of the simulation motor and the braking force distribution ratio of the brake master cylinder, according to the following formula:
T c_trg ＝F piston_trg ·i 2
T a_FF ＝T c_trg -(a+1)(T m_cmd +T s )
wherein, F piston_trg Is the braking force of the master cylinder i 2 The speed ratio coefficient of a second gear and a second rack in the third transmission mechanism is obtained; t is c_trg A torque acting on the planet carrier for a brake master cylinder;
T a_FF the second torque; t is m_cmd The first torque; ts is the torque of the return spring to the sun gear; a represents a gear ratio of the ring gear to the sun gear.
In a specific possible embodiment, the brake master cylinder further comprises a second displacement sensor for detecting the displacement of the piston rod of the brake master cylinder;
the control device is further used for acquiring the displacement of the piston rod of the brake master cylinder required to move according to the braking force distribution proportion of the brake master cylinder, and controlling the power-assisted motor to push the piston rod to move to the displacement when the second displacement sensor detects that the displacement of the piston rod does not reach the displacement. And closed-loop control is realized on the power-assisted motor, so that the braking effect is improved.
In a specific embodiment, the control device is further configured to determine a third torque of the non-failed simulation motor or the non-failed assist motor according to the braking force distribution ratio of the master cylinder when the assist motor or the simulation motor fails, and control the non-failed simulation motor or the non-failed assist motor to output the third torque. When one of the motors fails, the other motors can still be used for braking, so that the reliability of the whole brake power-assisted system is improved.
In a specific possible embodiment, the control device may also be applied to a case where the electric vehicle is in an active braking state, and when the brake pedal is pressed down, the control device adopts the braking requirement corresponding to the brake pedal when it is determined that the braking requirement provided by the brake pedal is greater than the braking requirement of the active braking according to the set corresponding relationship between the position of the brake pedal and the braking requirement.
In a second aspect, a braking method for an electric vehicle is provided, which includes:
detecting braking information of the electric automobile;
acquiring a first torque of a simulation motor in the electric automobile according to the braking information of the electric automobile;
acquiring the braking requirement of the electric automobile according to the braking information of the electric automobile;
acquiring the battery capacity of a battery of the electric automobile;
determining the braking force distribution proportion of a motor and a brake master cylinder in the electric automobile according to the driving state of the electric automobile, the braking demand of the electric automobile and the battery capacity of the electric automobile;
determining a second torque of the power-assisted motor according to the first torque of the simulation motor and the braking force distribution proportion of the brake master cylinder;
controlling the simulation motor to output the first torque and controlling the power-assisted motor to output the second torque;
the simulation motor and the power-assisted motor respectively output a first torque and a second torque which act on a piston rod in a brake master cylinder in the electric automobile to move.
In the technical scheme, the output torques of the simulation motor and the booster motor are simultaneously used as the force for driving the piston rod of the brake master cylinder, so that the output power requirement of a single motor can be improved. In addition, when the two motors are adopted to drive the brake master cylinder simultaneously, when one motor fails, the other motor can be used for braking, and the reliability of the whole brake power assisting system is improved. The active braking mode or the power-assisted braking mode can be selected according to the driving state of the electric automobile, the active braking mode can be adopted when the electric automobile is in an automatic driving state, and the power-assisted braking mode can be adopted when the electric automobile is in a personnel driving state.
In a specific possible embodiment, the obtaining of the braking demand of the electric vehicle according to the braking information of the electric vehicle includes:
acquiring the braking requirement of the electric automobile according to an ADAS system in the electric automobile; or detecting the position of a brake pedal in the electric automobile, and acquiring the braking demand of the electric automobile according to the position of the brake pedal and the set corresponding relation between the position of the brake pedal and the braking demand. The braking information of the electric automobile is obtained in different modes.
In a specific possible embodiment, the method further comprises: acquiring the braking force of the brake pedal according to the position of the brake pedal and the set corresponding relation between the position of the brake pedal and the braking force of the brake pedal;
acquiring a rotation angle of a sun gear in the electric automobile according to the position of the brake pedal and the braking force distribution proportion of the brake master cylinder, and acquiring torque of a return spring on the sun gear according to the rotation angle of the sun gear and the elastic coefficient of the return spring in the electric automobile;
the sun gear is arranged in a planetary gear mechanism of a planetary row coupling node in the electric automobile, and the planetary row coupling node is used for converting the braking force of the brake pedal, the torque of the return spring on the sun gear, and first and second torques respectively output by the power-assisted motor and the simulation motor into acting force acting on a piston rod in the brake master cylinder. More accurate control of the power-assisted motor and the simulation motor. The decoupling of the brake pedal and the brake master cylinder can be realized by adopting the planet gear mechanism, namely the brake pedal can realize that the brake master cylinder can have different braking forces at the same position, and the brake master cylinder can be adjusted as required at the moment, so that the electro-hydraulic decoupling is realized.
In a specific possible implementation manner, the obtaining of the first torque of the simulated motor according to the braking information of the electric vehicle is in accordance with the following formula:
T b_trg ＝i 1 F padel
Figure GDA0003893334470000051
wherein, T m_cmd A represents a gear ratio of a ring gear to the sun gear for the first torque; t is s For the torque of the return spring to the sun gear, T b_trg Is the torque of the brake pedal, F padel As the braking force of the brake pedal, i 1 The speed ratio coefficient of a first gear and a first rack in the first transmission mechanism is obtained;
the gear ring and the first transmission mechanism are arranged in the planet row coupling node, the first rack is connected with the brake pedal, the first gear is meshed with the first rack, and the first gear is fixedly connected with the gear ring and coaxially arranged.
In a specific embodiment, the second torque of the assist motor is determined according to the first torque of the simulation motor and the braking force distribution ratio of the master cylinder, and the following formula is satisfied:
T c_trg ＝F piston_trg ·i 2
T a_FF ＝T c_trg -(a+1)(T m_cmd +T s )
wherein, F piston_trg Is the braking force of the master cylinder i 2 The speed ratio coefficient of a second gear and a second rack in the third transmission mechanism is set; t is c_trg The torque acting on the planet carrier for the brake master cylinder;
T a_FF is said secondTorque; t is m_cmd The first torque; ts is the torque of the return spring to the sun gear; a represents a gear ratio of the ring gear to the sun gear;
the first transmission mechanism and the planet carrier are arranged in the planet row coupling node, the second rack is fixedly connected with a piston rod of the brake master cylinder, the second rack is meshed with the second gear, and the second gear is fixedly connected with the planet carrier and coaxially arranged.
In a specific possible embodiment, the method further comprises:
detecting a first displacement amount of a piston rod of the brake master cylinder;
and according to the braking force distribution proportion of the brake boosting system, acquiring a second displacement amount of the piston rod of the brake master cylinder, which needs to move, and controlling the boosting motor to push the piston rod to move to the second displacement amount when the first displacement amount does not reach the second displacement amount. And closed-loop control of the power-assisted motor is realized.
In a specific possible embodiment, the method further comprises:
and when the power-assisted motor or the simulation motor fails, determining a third torque of the non-failed simulation motor or the non-failed power-assisted motor according to the braking force distribution proportion of the brake master cylinder, and controlling the non-failed simulation motor or the non-failed power-assisted motor to output the third torque. The reliability of the brake boosting system is improved.
In a specific possible embodiment, the method further comprises: when the electric automobile is in an active braking state, and the brake pedal is stepped down, the control device adopts the brake demand corresponding to the brake pedal when the brake demand provided by the brake pedal is determined to be greater than the brake demand of the active braking according to the corresponding relation between the set position of the brake pedal and the brake demand.
In a third aspect, an electric vehicle is provided, which includes a vehicle body, a battery disposed on the vehicle body, and the brake boosting system described in any one of the above. In the technical scheme, the output torques of the simulation motor and the booster motor are simultaneously used as the force for driving the piston rod of the brake master cylinder, so that the requirement on the output power of a single motor can be improved. In addition, when the two motors are adopted to drive the brake master cylinder simultaneously, when one motor fails, the other motor can be used for braking, and the reliability of the whole brake power assisting system is improved.
Drawings
FIG. 1 is a prior art braking flow diagram of an electric vehicle;
FIG. 2 is a schematic diagram of a prior art brake boosting system;
FIG. 3a is a schematic structural view of the planetary gear mechanism;
FIG. 3b is an equivalent lever diagram for force analysis of the planetary gear mechanism;
FIG. 4 is a schematic structural diagram of a brake boosting system provided by an embodiment of the present application;
FIG. 5 is a schematic diagram of a brake boosting system provided by an embodiment of the present application;
FIG. 6 is a schematic diagram of a coupling node of a planet row according to an embodiment of the present application;
FIG. 7 is a force analysis diagram of a brake boosting system according to an embodiment of the present application;
FIG. 8 is a control block diagram provided by an embodiment of the present application;
FIG. 9 is a brake pedal and corresponding brake force profile provided by an embodiment of the present application;
FIG. 10a is a force analysis diagram of a brake booster system when braking is performed solely by the brake booster system according to an embodiment of the present application;
FIG. 10b is a force analysis diagram of the brake servo system during braking of the motor braking and the brake servo system according to the embodiment of the present disclosure;
FIG. 10c is a diagram illustrating a force analysis of the brake boosting system during braking of the motor according to an embodiment of the present application;
FIG. 11a is a force analysis diagram of a brake booster system when braking is performed solely by the brake booster system according to an embodiment of the present disclosure;
FIG. 11b is a force analysis diagram of the brake servo system during braking of the motor braking and the brake servo system according to the embodiment of the present disclosure;
FIG. 11c is a force analysis diagram of the brake boosting system during braking of an individual motor according to the embodiment of the present application;
FIG. 12a is a force analysis diagram of a brake boosting system in the event of a failure of a boosting motor according to an embodiment of the present application;
FIG. 12b is a force analysis graph of the brake boosting system in case of failure of the simulation motor according to the embodiment of the present application;
FIG. 12c is a force analysis diagram of a brake boosting system in case of failure of a simulation motor and a boosting motor according to an embodiment of the present disclosure;
FIG. 13a is a force analysis diagram of a brake boosting system in case of failure of a boosting motor according to an embodiment of the present application;
FIG. 13b is a force analysis diagram of a brake boosting system under failure condition of a simulation motor according to an embodiment of the present application;
FIG. 14 is a flow chart of a braking method provided by an embodiment of the present application;
FIG. 15 is a flowchart of a brake mode selection and planetary gear mechanism node reference command calculation provided by an embodiment of the present application;
FIG. 16 is a flowchart illustrating calculation of a motor torque command in a brake boosting system according to an embodiment of the present disclosure;
fig. 17 is a control flowchart of a brake assist system according to an embodiment of the present application.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application more clear, the present application will be further described in detail with reference to the accompanying drawings. The particular methods of operation in the method embodiments may also be applied to apparatus embodiments or system embodiments. In the description of the present application, the term "plurality" means two or more unless otherwise specified.
To facilitate understanding of the embodiments of the present application, several concepts are first explained:
a planetary gear mechanism: as shown in fig. 3a, the planetary gear mechanism includes: ring gear (R), planet carrier (C) and sun gear (S)) Wherein the planet carrier (C) is rotationally connected with the gear ring (R) through the planet wheel (P), and the sun wheel (S) is rotationally connected with the planet wheel (P). In the case of a planetary gear set, which is used for the analysis of movements and forces, the lever method is used, as shown in fig. 3b, in which the sun gear and the ring gear are arranged on both sides of the planet carrier in the equivalent lever diagram, since the ring gear and the sun gear move in opposite directions in the movement relative to the planet carrier. As shown in FIG. 3b, the motion angle displacement of the three parts of the gear ring, the planet carrier and the sun gear is respectively theta R (ring gear), theta c (planetary carrier), θ s (sun gear) for applying force by T R_ext (the ring gear),
Figure GDA0003893334470000081
(the planet carrier),
Figure GDA0003893334470000082
(sun gear). The three components have constraint relation in the planetary gear mechanism, and can be represented by the following three formulas:
Figure GDA0003893334470000083
Figure GDA0003893334470000084
aθ R +θ s ＝(1+a)θ c (3)
through the three formulas, the stress and the motion of the planet wheel are similar to the stress of the lever, so that the stress and the motion of the planet gear mechanism are analyzed more intuitively by using a lever diagram, and an equivalent result is shown in fig. 3 b. The gear ratio of the planetary gear mechanism is expressed by the length ratio of the levers as shown in fig. 3b, and further, 1: a is the gear ratio of the ring gear to the sun gear. The rotational movement of the planetary gear mechanism is replaced by a translational movement of the lever node (length of the dashed arrow in fig. 3 b), which replaces the torque to which the planetary gear mechanism is subjected by a horizontal force (solid arrow in fig. 3 b).
Electro-hydraulic brake decoupling (electro-hydraulic decoupling for short): the decoupling control of motor braking and hydraulic braking is realized. The recovery efficiency of the braking energy of the whole vehicle is improved.
In order to facilitate understanding of the brake boosting system provided in the embodiments of the present application, an electric vehicle is first described, and the electric vehicle includes a battery and a motor connected to the battery, where the motor is a driving motor for providing power for the electric vehicle. And when braking, the motor can also be driven to rotate by the wheels, and the motor is used as a generator to supply power to the battery so as to recover kinetic energy. In addition, the electric vehicle has a special hydraulic brake system, as shown in fig. 1, fig. 1 shows two different paths of the vehicle in the prior art when braking, and the first path is: the braking force acts on the wheels through a brake boosting mechanism, a hydraulic brake system and a brake caliper; the second path is that the driving motor generates reverse torque to directly act on the wheel, so as to realize braking. The brake boosting system provided by the embodiment of the present application is a mechanism for performing braking by using a first path, and the brake boosting system provided by the embodiment of the present application is described in detail below with reference to the accompanying drawings and specific embodiments.
Referring to fig. 4 and 5 together, fig. 4 shows a schematic structural diagram of a brake boosting system provided in an embodiment of the present application, and fig. 5 shows a schematic structural diagram of the brake boosting system provided in the embodiment of the present application. The brake boosting system provided by the embodiment of the application comprises a brake pedal 10, a simulation motor 20 and a boosting motor 30. The brake pedal 10 is configured to be stepped on by a driver during a braking operation, and like the brake pedal 10 in the related art, the simulation motor 20 is configured to simulate a pedal force of the brake pedal 10 and provide different pedal forces according to a stepping depth of the brake pedal 10, and the booster motor 30 is configured to assist in driving the master cylinder 40 for braking. The brake power assisting system further comprises a master cylinder 40, and the electric vehicle is braked by the master cylinder 40. The brake pedal 10, the simulation motor 20, and the booster motor 30 are connected to the planet row coupling node 100 to apply force to the brake master cylinder 40, and the brake master cylinder 40 brakes the electric vehicle. The following describes in detail the specific connection of the above-mentioned components.
Referring to fig. 4 and fig. 6 together, fig. 6 shows a schematic diagram of a coupling node of a planet row according to an embodiment of the present application. The planetary row coupling node 100 of the embodiment of the present application includes: a first transmission 60, a second transmission 70, a third transmission 80 and a planetary gear 50, wherein the planetary gear 50 is as shown in fig. 3a, comprising a ring gear 52, a planet carrier 51 and a sun gear 53. With continued reference to fig. 4 and 6, the brake pedal 10 is connected to the ring gear 52 of the planetary gear mechanism 50 through a first transmission mechanism 60, and the ring gear 52 is driven to rotate through the first transmission mechanism 60, as shown in fig. 4, the first transmission mechanism 60 may be a rack and pinion mechanism including a first rack 62 connected to the brake pedal 10 and a first gear 61 engaged with the first rack 62, and the first gear 61 is fixedly connected to and coaxially disposed with the ring gear 52. When the brake pedal 10 is pressed, the brake pedal 10 rotates and drives the first rack 62 to move along a straight line, and the first rack 62 drives the first gear 61 to rotate, so as to drive the gear ring 52 to rotate. When depressed, the brake pedal 10 generates a torque, referred to simply as a torque of the brake pedal 10, to the planetary gear mechanism 50. It should be understood that only a rack and pinion mechanism is shown as the first transmission mechanism 60 in fig. 4, but the first transmission mechanism 60 provided in the embodiment of the present application is not limited to the rack and pinion mechanism, and other known transmission mechanisms that can convert linear motion into rotational motion may be adopted.
With continued reference to fig. 4 and 6, when the axial direction of the booster motor 30 is perpendicular to the axial direction of the planetary gear mechanism 50, and the axial direction of the booster motor 30 is perpendicular to the axial direction of the planetary gear mechanism 50, as shown in fig. 4, the space occupied by the brake booster system in the axial direction of the planetary gear mechanism 50 can be reduced, and the space occupied by the entire brake booster system can be improved. The booster motor 30 is connected to the carrier 51 of the planetary gear mechanism 50 via a second transmission mechanism 70. The second transmission mechanism 70 may adopt a worm gear 72 and worm 71 mechanism, as shown in fig. 4, the assist motor 30 is connected with a worm 71, the planet carrier 51 is fixedly connected and coaxially provided with a worm gear 72, and the worm 71 is meshed with the worm gear 72. When the assist motor 30 works, the output shaft of the assist motor 30 is fixedly connected with the worm 71, and when the output shaft rotates, the worm 71 is driven to rotate, the worm 71 drives the worm wheel 72 to rotate so as to drive the planet carrier 51 to rotate, and meanwhile, the assist motor 30 generates a torque to the planet carrier 51, which is referred to as the torque of the assist motor 30. The second transmission mechanism 70 provided in the embodiment of the present application is not limited to the worm wheel 72 and worm 71 mechanism, and for example, the second transmission mechanism 70 employs a bevel gear set. When the bevel gear set is adopted, a first bevel gear of the bevel gear set is connected with the power-assisted motor 30, a second bevel gear is fixedly connected with the planet carrier 51 and coaxially arranged, the first bevel gear is meshed with the second bevel gear, and the power-assisted motor 30 can drive the planet carrier 51 to rotate. When the bevel gear matching is adopted, the arrangement position of the power-assisted motor 30 can be selected more. If bevel gears with different tapers are selected, the axis of the power-assisted motor 30 and the axis of the planetary gear mechanism 50 can form different angles, and the selection is more flexible. Or when the axis of the booster motor 30 and the axis of the booster motor 30 are the same axis or parallel, other common transmission mechanisms may be adopted to drive the planet carrier 51 to rotate.
With continued reference to fig. 4 and 6, the axis of the simulation motor 20 is the same as the axis of the planetary gear mechanism 50, and the simulation motor 20 is connected to the sun gear 53 of the planetary gear mechanism 50 and is used for driving the sun gear 53 to rotate. When the simulation motor 20 works, the output shaft of the simulation motor 20 is directly connected with the sun gear 53, so that the sun gear 53 is directly driven to rotate, and the torque of the simulation motor 20 is the torque directly acting on the planetary gear mechanism 50. When the axis of the simulation motor 20 is parallel to but not coaxial with the axis of the planetary gear mechanism 50, other transmission mechanisms may be used to connect the simulation motor 20 and the sun gear 53, such as a coupling, or other common transmission mechanisms. In addition, when the axis of the simulation motor 20 is not parallel to the axis of the planetary gear mechanism 50, the connection between the simulation motor 20 and the sun gear 53 can be realized by referring to the transmission manner of the assist motor 30.
Referring to fig. 3b and 4 together, the brake pedal 10 drives the ring gear 52 to rotate, and the simulation motor 20 is connected with the sun gear 53, while in the stress analysis of the planetary gear mechanism 50 shown in fig. 3b, it can be seen that the ring gear 52 and the sun gear 53 are arranged on two sides of the planet carrier 51, and it can be seen that the planet carrier 51 is taken as a fulcrum, and the stress of the ring gear 52 and the sun gear 53 is applied to two ends of the lever, therefore, although the force applied by the simulation motor 20 and the brake pedal 10 acts on the planetary gear mechanism 50 in the same direction, the simulation motor 20 can still simulate the pedal force of the brake pedal 10.
With continued reference to fig. 4 and 6, the axis of the master cylinder 40 is perpendicular to the axis of the planetary gear mechanism 50, and the master cylinder 40 is a hydraulic cylinder commonly known in the art, and includes a cylinder body and a piston rod 41 slidably connected with the cylinder body. When connected to the planetary gear mechanism 50, the brake master cylinder 40 is connected to a second rack 82, the carrier 51 is fixedly connected to a second gear 81 coaxially disposed, and the second rack 82 is meshed with the second gear 81. When the planet carrier 51 rotates, the second gear 81 is driven to rotate, and the second gear 81 drives the second rack 82 to slide so as to drive the piston rod 41 to slide, so that the brake master cylinder 40 is driven to work and braking force acting on the wheels of the electric automobile is provided. The second rack 82 and the second gear 81 serve as the third transmission mechanism 80 to realize that the planet carrier 51 pushes the piston rod 41 to make a linear motion. Of course, the third transmission mechanism 80 is not limited to the rack and pinion mechanism, and other structures capable of converting rotational motion into linear motion can be adopted.
With continued reference to fig. 4, the planetary gear train coupling node 100 further includes a return spring 90, the return spring 90 is a torsion spring, the planetary gear train 50 further includes a housing (not shown) enclosing the ring gear 52, the planet carrier 51 and the sun gear 53, one end of the torsion spring is fixed on the housing, and the other end is fixed on the sun gear 53. When the simulation motor 20 drives the sun gear 53 to rotate, the torsion spring deforms, and after the simulation motor 20 stops, the sun gear 53 is pushed to rotate reversely by the elastic force of the torsion spring and returns to the initial position.
Referring to fig. 5 and 6, the planet row coupling node 100 further includes a limiting device 200, and the limiting device 200 is used for limiting the rotation of the sun gear 53 to a set angle. When the limiting device 200 is specifically arranged, the direction of the limiting device 200 for limiting the rotation of the sun gear 53 is opposite to the direction of the simulation motor 20 driving the sun gear 53 to rotate, so that when the simulation motor 20 fails, the sun gear 53 can rotate in the reverse direction under the driving of the planet carrier 51, and when the sun gear 53 rotates in the reverse direction by a set angle, the limiting device 200 limits that the sun gear 53 cannot rotate continuously when rotating to the set angle.
Referring to fig. 7, fig. 7 shows a force analysis diagram of a brake boosting system provided by an embodiment of the present application. The dashed arrows indicate the direction of movement of the planetary gear mechanism. The planetary gear mechanism 50 is adopted in the planet row coupling node 100, and as can be seen from the above description, the stress of the planetary gear mechanism 50 can be equivalent to a lever stress analysis, so the planetary gear mechanism 50 is equivalent to a lever in fig. 7. In FIG. 7T b Torque generated to the ring gear 52 for the brake pedal 10; t is m To simulate the torque generated by motor 20 on sun gear 53; t is a Torque generated to the carrier 51 for the assist motor 30; t is c Torque generated to the carrier 51 for the master cylinder 40; t is s Is the torque generated by return spring 90 on sun gear 53. a is the gear ratio of the ring gear 52 to the sun gear 53. Theta R Is the rotation angle of the ring gear 52, i.e., the angular displacement of the brake pedal 10; theta c The rotation angle of the planet carrier 51, namely the angular displacement of the booster motor 30 (or the brake master cylinder 40); theta s The angle of rotation of sun gear 53, i.e., the angular displacement of motor 20, is simulated.
When the planetary gear mechanism is adopted, the following three formulas can be obtained from the above formulas (1), (2) and (3):
T b ＝a(T m +T s ) (4)
T c -T a ＝T b +T m +T s (5)
aθ R +θ s ＝(1+a)θ c (6)
from the above equation (5), T can be seen c ＝T a +T b +T m +T s . That is, the torque applied to the planet carrier by the brake master cylinder is equal to the torque of the brake pedal, the torque of the power-assisted motor, the torque generated by the return spring to the sun gear and the torque of the simulation motor, so that the torque provided by the embodiment of the application can simultaneously work on the brake master cylinder to push the brake master cylinder to drive the electric steam to act on the electric steamThe wheels of the vehicle are braked. Of course, the return spring may be an alternative device, and when the return spring is not provided, T c ＝T a +T b +T s When the planet carrier is used, namely the torque acted on the planet carrier by the brake master cylinder is provided by the torque of the brake pedal, the torque of the power-assisted motor and the torque of the simulation motor, and the planet row coupling node is used for converting the torque of the brake pedal, the torque output by the power-assisted motor and the torque output by the simulation motor into acting force acted on a piston rod in the brake master cylinder.
When the electric automobile needs to be braked, the electric automobile has two ways: motor braking and braking power-assisted system braking. When different braking modes are selected, the braking mode is determined according to the battery amount of the electric automobile. When the battery capacity is good, the battery does not need to be reversely charged, and an independent brake power assisting system can be adopted for braking. When the battery needs to be charged, the motor braking and the braking assistance system braking can be selected to be carried out simultaneously, or the motor braking can be carried out independently. The brake boosting system will be described in detail below in connection with the different operating modes described above.
As shown in fig. 8, fig. 8 is a block diagram showing a control structure of the brake assist system. The brake assisting System provided by the embodiment of the application further comprises a first detection device and a second detection device, wherein the first detection device is used for acquiring brake information of the electric automobile, the first detection device can be a first displacement sensor for detecting the position of a brake pedal or an Advanced Driver Assistance System (Advanced driving Assistance System) of the electric automobile, the ADAS can adopt an existing ADAS, and detailed description of specific implementation modes of the ADAS is omitted. When the first detection device is the first displacement sensor, the braking information of the electric vehicle is the position of the brake pedal. The second detection device is used for detecting the battery capacity of the battery of the electric automobile, and the second detection device can adopt an existing electric quantity sensor or other common sensors for detecting the battery capacity.
With continued reference to fig. 8, the brake boosting system provided in the embodiment of the present application further includes a control device, and the control device is respectively connected to the first detection device, the second detection device, the boosting motor, the simulation motor, and the master cylinder. During control, the control device acquires the braking demand of the electric automobile according to the braking information of the electric automobile detected by the first detection device, and when the first detection device is a first displacement sensor, the control device acquires the braking demand of the electric automobile according to the position of the brake pedal detected by the first displacement sensor and the set corresponding relation between the position of the brake pedal and the braking demand. When the ADAS system is adopted, the control device can directly acquire the braking demand from the ADAS system.
In addition, the control device determines the braking force distribution ratio of the motor of the electric automobile and the brake master cylinder according to the braking demand of the electric automobile and the battery quantity of the battery of the electric automobile acquired by the second detection device. When the electric automobile is specifically determined to be braked by a motor or a brake boosting system, if the battery amount reaches a set value which can be 70%, 80% or 90% of the full electric quantity according to the reference of the battery amount, the motor is judged not to need to be charged, and at the moment, the brake boosting system is only selected for braking, namely, the brake boosting system provides one hundred percent of braking requirements. When the battery amount is smaller than a set value, the battery is judged to need to be charged, and at the moment, the control device controls to brake the motor and the brake power assisting system or only adopts the motor to brake. When the simultaneous braking is adopted, the braking force distribution proportion of the motor braking and the braking of the braking assistance system is divided according to the amount of the battery, and the braking force distribution proportion can be adjusted according to actual needs, and is not particularly limited herein.
When the control device obtains the braking information of the electric vehicle, the control device may obtain the first torque of the analog motor according to the braking information. Taking the first detecting device adopting the first displacement sensor as an example, the control device may obtain the braking force of the brake pedal according to the position of the brake pedal detected by the first displacement sensor and the corresponding relationship between the position of the brake pedal and the braking force of the brake pedal; wherein the braking force of the brake pedal is the pedal force of the brake pedal. The position of the brake pedal and the pedal force of the brake pedal can be set through set curves, such as three curves in fig. 9Different pedal curves can be selected by the driver according to requirements by different curves f1, f2 and f 3. Braking force of the brake pedal is F padel Position of the brake pedal is S padel Then, formula 7 is satisfied:
F padel ＝f i (S padel ),i＝1,2,3… (7)
the control device is based on the actual position S of the brake pedal detected by the first displacement sensor padel And the corresponding curve in fig. 9 (i.e., equation 7) calculates the pedal force that needs to be simulated by the simulated motor, and thus calculates the torque T of the brake pedal b_trg That is, a target value of torque applied to the ring gear in the planetary gear mechanism, as shown in the following equation:
T b_trg ＝i 1 F padel (8)
wherein i 1 The gear ratio coefficient of a first gear and a first rack in the first transmission mechanism.
The control device can obtain the first torque of the simulation motor according to the force analysis of the planetary gear mechanism and a formula 8:
Figure GDA0003893334470000131
wherein, T m_cmd A represents a gear ratio of the ring gear to the sun gear; t is s Torque of the return spring to the sun gear, T b_trg Torque of brake pedal, F padel To brake pedal braking force, i 1 The speed ratio coefficient of a first gear and a first rack in the first transmission mechanism.
In determining T s The control device acquires the rotation angle of the sun gear according to the position of the brake pedal detected by the first displacement sensor and the braking force distribution proportion of the brake master cylinder, and acquires the torque of the return spring to the sun gear according to the rotation angle of the sun gear and the elastic coefficient of the return spring. Because the return spring only plays a role in returning in the embodiment of the application, T can be approximately considered to be T in a normal working mode s A small constant value. Of course, there is no return in the brake booster systemWhen the spring is in place, then T s ＝0。
When the electric automobile adopts the ADAS system to realize automatic driving, and the brake pedal cannot be stepped down at the moment, the corresponding braking force F of the brake pedal at the initial position is obtained according to the formula 7 padel To obtain a first torque simulating the motor.
After determining the first torque of the simulation motor, the control device may determine the second torque of the assist motor according to the acquired first torque and the braking force distribution ratio of the master cylinder. After the braking force distribution ratio of the master cylinder is obtained, the braking force required to be provided by the master cylinder can be determined.
When determining the second torque of the assist motor, the second torque T of the assist motor may be calculated according to the braking force of the brake master cylinder, the second torque of the simulation motor, and the force relationship of the planetary gear mechanism, according to equations 10 and 11 a_FF
T c_trg ＝F piston_trg ·i 2 (10)
T a_FF ＝T c_trg -(a+1)(T m_cmd +T s ) (11)
Wherein, F piston_trg For braking the braking force of the master cylinder, i 2 The speed ratio coefficient of a second gear and a second rack in the third transmission mechanism is set; t is a unit of c_trg The torque acting on the planet carrier for the brake master cylinder;
T a_FF a second torque; t is m_cmd Is a first torque; ts is the torque of the return spring to the sun gear; a represents a gear ratio of the ring gear to the sun gear.
After determining the first torque of the simulation motor and the second torque of the power-assisted motor, the control device controls the power-assisted motor and the simulation motor to output the first torque and the second torque respectively, and brakes the electric automobile through the brake master cylinder.
With continued reference to FIG. 8, when the braking force of the master cylinder is determined, the piston rod is actuated according to the torque output from the planetary gear mechanism to form a stroke S of the master cylinder piston Relation between braking force of master cylinderThe characteristic of (b) satisfies equation 12:
F piston_trg ＝g(S piston ) (12)
and g is a performance curve of the brake master cylinder, the curve corresponding to each brake master cylinder is unique, and the performance curve can be obtained from the performance parameters of the brake master cylinder.
After the braking force required to be provided by the master cylinder is determined, the stroke of the master cylinder, that is, the distance that the piston rod of the master cylinder needs to move, can be determined by equation 12.
The brake boosting system provided by the embodiment of the application further comprises a second displacement sensor for the displacement of the piston rod of the brake master cylinder. The displacement of the piston rod is the stroke S of the brake master cylinder piston The control device is also used for acquiring the displacement amount of the piston rod of the brake master cylinder required to move, namely the stroke S of the brake master cylinder required to move according to the braking force distribution proportion of the brake master cylinder piston And when the second displacement sensor detects that the displacement of the piston rod does not reach the displacement amount, controlling the power-assisted motor to push the piston rod to move to the displacement amount. In the scheme, the brake master cylinder is controlled in a closed loop mode, and the brake effect of the electric automobile is guaranteed. Of course, the stroke of the brake master cylinder is used as a reference for closed-loop control, and the angular displacement of the planet carrier connected with the brake master cylinder can also be used as a reference for closed-loop control, and at this time, the difference value between the angular displacement of the planet carrier and the target angular displacement is detected, and the power-assisted motor is controlled to push the planet carrier to rotate to the target angular displacement.
In order to facilitate understanding of the working principle of the brake boosting system provided in the embodiment of the present application, different braking situations are described below. The braking mode of the electric automobile is divided firstly, and in the embodiment of the application, the braking mode is divided into two types: a power-assisted braking mode and an active braking mode. The power-assisted braking mode is a braking mode in which a driver participates, namely a braking mode performed by stepping on a brake pedal by the driver, and at the moment, the first detection device is a first displacement sensor. The active braking mode is a braking mode of the electric vehicle in an automatic driving state, namely braking during automatic driving is performed through the ADAS system, and at the moment, the first detection device is the ADAS system.
Firstly, an assisted braking mode is explained, and fig. 10a to fig. 10c are referred together, wherein fig. 10a shows a stress analysis diagram of a brake assisting system when the brake assisting system is solely braked (sub-mode 1), and fig. 10b shows a stress analysis diagram of the brake assisting system when the motor brake and the brake assisting system are braked (sub-mode 2); fig. 10c shows a force analysis diagram of the brake booster system during motor braking (sub-mode 3).
In fig. 10a to 10c, T can be obtained according to the force analysis formula 2 of the planetary gear mechanism, all satisfying the force analysis formula 2 of the planetary gear mechanism c ＝T a +T b +T m +T s Wherein the brake pedal (applied torque T) b ) And a booster motor (acting torque T) a ) Analog motor (acting torque T) m ) And a return spring (acting torque T) s ) Acting together on the master cylinder (acting torque T) c ). The pressure generated by the brake master cylinder is the combined force of the four. Therefore, under the same boosting effect, the torque and power requirements of a single motor (a simulation motor or a boosting motor) are lower in the embodiment of the application.
When a driver steps on the brake pedal, the power-assisted motor can push the master cylinder to move to a corresponding position theta according to the position of the brake pedal c . The following formula can be obtained according to the planetary gear mechanism stress analysis formula 6:
Figure GDA0003893334470000151
angular displacement theta of brake pedal R Decoupled from the displacement of the master cylinder (corresponding to the hydraulic braking force of the vehicle), i.e. at the same brake pedal displacement theta R The brake master cylinder can have different displacements (such as a sub-mode 1, a sub-mode 2 and a sub-mode 3), so that the braking force of the brake power-assisted system can be adjusted according to requirements, and electro-hydraulic decoupling is realized.
Formula 1T for analyzing stress of planetary gear mechanism b ＝a(T m +T s ) Therefore, the simulation motor adjusts the torque T according to the requirement m Thereby adjusting the torque T at the brake pedal b . From the formula 2T c ＝T a +T b +T m +T s It can be known that the booster motor T is synchronously adjusted a Can maintain the brake master cylinder torque T c Not changing, and thus keeping the angular displacement of the components of the planetary gear mechanism (i.e. theta) R 、θ s 、θ c Does not change). Therefore, the electronic regulation of the pedal force simulation curve of the brake pedal can be realized through the coordination control of the simulation motor and the power-assisted motor.
When the sub-mode 1 singly adopts the brake power-assisted system for braking, the pressure of the brake master cylinder is highest, and the corresponding angular displacement theta of the planet carrier is c And maximum. In the mode that the brake boosting system and the motor are simultaneously braked in the sub-mode 2, as the motor brake shares part of brake force, the required brake force of the brake boosting system is reduced compared with the sub-mode 1, and therefore theta c And correspondingly reduced. In the pure electric braking mode in the sub-mode 3, the braking force of the electric automobile is recovered by the electric motor, the main braking cylinder does not build pressure, theta c ＝0。
As can be seen from FIGS. 10 a-10 c, the assist motor T is operated in three braking modes a And simulating motor torque T m The brake pedal is controlled to be adjusted, so that the stress of the brake pedal is kept consistent, and the drivers feel consistent in different modes.
Therefore, in the embodiment of the application, the following can be realized:
(1) Different power-assisted curves can be selected to achieve different pedal sensations (electronic regulation of the pedal force simulation curve of the brake pedal).
(2) And flexibly adjusting the position of a brake master cylinder and the torque of the simulated motor according to the braking force distribution proportion of the motor brake and the brake power-assisted system brake, so that the pedal-braking force relation and the pedal feeling of a driver are kept consistent under different working conditions.
(3) And in different modes, the driver feels consistent.
Next, the active braking mode is described, and fig. 11a to 11b are also referred to, in which fig. 11a shows a stress analysis diagram of the brake servo system when braking by the brake servo system alone (mode 4), and fig. 11b shows a stress analysis diagram of the brake servo system when braking by the motor and the brake servo system (mode 5).
In the active braking mode, braking information of the electric automobile is acquired through the ADAS system, a driver does not need to step on a brake pedal, so that the brake pedal keeps the initial position still, and the brake pedal can only move at the right side of the initial position under the action of a pedal limiting device (the pedal limiting device is a device in the prior art and is not described here), so that in the state, torque Tb of the brake pedal comes from the reverse acting force of the pedal limiting device, tb is driven force, and in the stress analysis of the graphs in the fig. 11a to 11c, the drawing is omitted.
In the active braking mode, the brake master cylinder can be pushed by the aid of the power motor or the simulation motor, but the power motor and the simulation motor can work simultaneously.
Referring to fig. 11a to 11b together, the stress analysis of the brake boosting system in the active braking mode is performed:
in the active braking mode, the brake pedal is required to remain in place:
θ R ＝0
from equation 6, it can be found that:
the angular displacement relationship of the brake master cylinder and the simulation motor is as follows:
Figure GDA0003893334470000161
according to the formulas 4 and 6, the torque of the brake master cylinder and the torque of the power-assisted motor, the torque of the brake pedal and the torque of the simulation motor satisfy the formula 13:
T c ＝(a+1)T m +T a -T s (13)
the angular displacement theta of the brake master cylinder can be obtained by the formula c And torque T c Can be realized by the combined drive of the booster motor and the simulation motorA target value of the demand. Therefore, when the brake pedal is maintained in the original position, the decoupling of the required brake pedal and the hydraulic braking force can be realized according to the braking requirement of the ADAS.
Fig. 11a to 11c show the working states of the brake boosting system of the present application in three different sub-modes under the same total braking force demand.
In the sub-mode 4, as shown in fig. 11a, since all the braking force is derived from the brake booster system, the braking force of the brake booster system is maximized, and the angular displacement θ of the master cylinder is increased c Maximum, corresponding master cylinder torque T c And is also the highest. In the sub-mode 5, as shown in fig. 11b, since a part of the braking force is realized by the electromechanical braking, the braking force of the brake assist system is reduced, and the angular displacement θ of the master cylinder is reduced c And (4) reducing. In the sub-mode 6, as shown in fig. 11c, all the braking energy is realized by the electric braking of the motor, and the braking force of the braking assistance system is zero, so that the braking assistance system maintains the original position, and the simulation motor and the assistance motor can be in the off state and do not work.
In the use process of the electric automobile, the problem of failure of a motor in a brake boosting system cannot be avoided. The motor failure modes in the brake boosting system are divided into three types: the assist motor fails, the simulation motor fails, and both fail. When the motor fails, the control device is also used for determining the third torque of the non-failed simulation motor or the non-failed power-assisted motor according to the braking force distribution proportion of the brake master cylinder when the power-assisted motor or the simulation motor fails, and controlling the non-failed simulation motor or the non-failed power-assisted motor to output the third torque. The following description will be made with reference to the accompanying drawings, respectively, for the failure of the assist motor, the failure of the simulation motor, or the failure of both the assist motor and the simulation motor.
Referring first to fig. 12 a-12 c, fig. 12 a-12 c show force analysis diagrams of the brake booster system in the event of a motor failure in the booster braking mode. As shown in fig. 12a, fig. 12a shows a specific case where the assist motor is in a failure condition. When the booster motor fails, the control device calculates the non-failed module according to the braking force distribution proportion of the brake master cylinderThe third torque of the electric machine can be simulated, which is no longer determined by the force of the brake pedal when specifically calculated. But the torque of the brake pedal and the third torque of the analog motor are simultaneously applied to the master cylinder to provide the force required for braking. As shown in fig. 12b, fig. 12b shows the situation when the simulated motor fails. When the simulation motor is invalid, the simulation motor can not provide the treading force corresponding to the brake pedal, and when the brake pedal is treaded, the limiting device limits the sun gear to rotate in the reverse direction under the driving of the planet carrier and the sun gear can not rotate continuously after the set angle is set. At this time, the torque of the brake master cylinder is equal to the sum of the torque of the brake pedal, the third torque of the assist motor and the torque provided by the limiting device. Fig. 12c shows the case where the booster motor and the simulation motor fail at the same time. At this time, only by stepping on the brake pedal, the limiting device can be acted after the sun gear of the planetary gear mechanism overcomes the idle stroke of the limiting device, so that pressure is generated on the main cylinder only through the brake pedal force, and here, due to the deceleration effect of the planetary gear mechanism, additional pedal force can be still carried out
Figure GDA0003893334470000171
The amplification of the times can ensure that the electric automobile can generate enough braking force and the safety of the automobile is ensured.
Referring to fig. 13a and 13b, fig. 13a and 13b illustrate a case where the motor fails in the active braking mode. As shown in fig. 13a, when the assist motor fails, the master cylinder is pushed by the dummy motor. As shown in fig. 13b, when the simulation motor fails, the master cylinder is pushed by the booster motor. However, in the active braking mode, since the brake pedal is not stepped on, when the simulation motor and the brake motor fail, the brake boosting system does not generate boosting force, so that the active braking function fails.
As can be seen from the above description, in the brake boosting system provided in the embodiment of the present application, when the boosting motor fails or the simulation motor fails, another execution motor can independently push the brake master cylinder, so that the boosting brake function and a part of the active brake function can still be realized. The reliability of the electric automobile brake is improved.
In addition, the control device can also be applied to the situation that the electric automobile is in an active braking state, when the brake pedal is stepped down, the control device adopts the braking requirement corresponding to the brake pedal when the braking requirement provided by the brake pedal is determined to be greater than the braking requirement of the active braking according to the set corresponding relation between the position of the brake pedal and the braking requirement.
The embodiment of the application also provides a braking method of an electric automobile, which applies the braking boosting system, and the method comprises the following steps:
detecting braking information of the electric automobile;
acquiring a first torque of a simulation motor in the electric automobile according to the braking information of the electric automobile;
acquiring the braking demand of the electric automobile according to the braking information of the electric automobile;
acquiring the battery capacity of a battery of the electric automobile;
determining the braking force distribution proportion of a motor and a brake master cylinder in the electric automobile according to the braking demand of the electric automobile and the battery capacity of the electric automobile;
determining a second torque of the power-assisted motor according to the first torque of the simulation motor and the braking force distribution proportion of the brake master cylinder;
controlling the simulation motor to output a first torque, and controlling the power-assisted motor to output a second torque;
the simulation motor and the power-assisted motor respectively output a first torque and a second torque which act on a piston rod in a brake master cylinder in the electric automobile to move.
The braking process provided by the embodiment of the present application is described in detail below with reference to fig. 14.
S1: detecting braking information of the electric automobile;
specifically, the current braking intensity requirement of the electric vehicle is obtained through a request sent by a driver for stepping on a brake pedal or a vehicle-mounted ADAS system. Reference may be made in particular to the above description of the control of the brake boosting system.
S2, acquiring the braking requirement of the electric automobile according to the braking information of the electric automobile;
specifically, the hydraulic braking force and the motor braking force are distributed to the electric vehicle according to the information of the vehicle speed, the steering, the vehicle body posture and the like of the electric vehicle, the SOC, the voltage, the temperature and the like of the battery, and then the braking force distribution ratio of the motor and the brake master cylinder in the electric vehicle is determined, which can be referred to the control description of the brake boosting system.
S3: selecting a braking mode and calculating a reference instruction of a node of the planetary gear mechanism;
as shown in fig. 15, the method specifically includes the following steps:
s31: and selecting an active braking mode and an assisted braking mode.
Determining to adopt an active braking mode or a power-assisted braking mode according to the driving state of the electric automobile, and specifically judging that the electric automobile should be in the active braking mode or the power-assisted braking mode according to information such as the position of a brake pedal, an ADAS system braking instruction, whether a driver starts an automatic driving mode or not, wherein the process adopts the prior art and is not described in detail herein.
When the active braking mode is switched to the power-assisted braking mode, when the brake pedal is stepped on, the control device determines that the braking demand provided by the brake pedal is larger than the braking demand of the active braking according to the corresponding relation between the set position of the brake pedal and the braking demand, and the control device adopts the braking demand corresponding to the brake pedal. I.e. from the active braking mode to the assisted braking mode. When the power-assisted braking mode is switched on, when the stepping amplitude of the brake pedal is small, the braking force provided by the brake power-assisted system is smaller than the braking force of active braking, so that the situation of reducing the braking force is avoided.
The motor braking mode only depends on the braking of the driving motor to realize the deceleration of the electric automobile, and the braking energy is recovered to the maximum extent. In the power-assisted braking mode, the motor braking may be coupled with the brake power-assisted system, or only the brake power-assisted system works (when the battery SOC is high), and specific reference may be made to the above description of the control of the brake power-assisted system.
S32: judging the current brake sub-mode according to the braking force distribution proportion condition of the motor and the brake master cylinder;
for the brake boosting system provided by the application, the control logic capable of realizing 6 brake modes is shown in table 1. In the step, a sub-mode in which a braking system should work is selected according to the working condition of the braking mode listed in the table 1 and the current distribution condition of the electro-hydraulic braking demand, and the control modes required by the power-assisted motor and the simulation motor are determined.
TABLE 1 different modes of operation of the brake system
Figure GDA0003893334470000191
Note: and √ denotes that there is a corresponding braking demand, and X denotes that the corresponding braking demand is 0. The position control means that the final rotation angle position of the executing motor is taken as a closed-loop control target, and the torque control means that the output torque of the executing motor is taken as a control target.
S33, calculating a target value of the pressure of the brake master cylinder and a target command theta of the position of the brake master cylinder according to the braking demand of the brake power assisting system c_trg ；
The brake torque is related to the hydraulic pressure of the brake master cylinder, and is determined by the design of a hydraulic pipeline, and the target value F of the hydraulic pressure of the brake master cylinder piston_trg The calculation of (a) is prior art and will not be described in detail herein.
The hydraulic pressure of the master cylinder is related to the stroke of the master cylinder and is determined by the characteristics of the master cylinder, and the target value S of the stroke of the master cylinder piston_trg Can be obtained by looking up a table, and the table can be obtained by using the prior art.
The brake master cylinder is connected with the planet carrier through the gear and the rack, so the target value S of the master cylinder stroke piston_trg Target command theta with planet carrier position c_trg Satisfies S piston_trg ＝θ c_trg /i 2 (ii) a Thus the angular displacement theta of the planet carrier c_trg The target value may be calculated from a stroke target value of the master cylinder:
θ c_trg ＝S piston_trg /i 2
wherein i 2 The gear ratio coefficient of a third gear and a third rack of the third transmission mechanism.
S34, calculating the torque T of the brake pedal needing to be simulated according to the position of the brake pedal b_trg
The pedal force of the brake pedal can be set by a set curve, such as the three different curves in the setting of fig. 9, selected by the driver. Expressed by equation 7:
F padel ＝f i (S padel ),i＝1,2,3…
the control device detects the actual position S of the brake pedal according to the first displacement sensor padel And the corresponding curve in fig. 9 (i.e., equation 7) calculates the pedal force that the simulated motor needs to simulate, and thus calculates the torque T of the brake pedal b_trg I.e. the torque applied to the ring gear in the planetary gear mechanism, as shown in formula 8:
T b_trg ＝i 1 F padel
wherein i 1 The gear ratio coefficient of a first gear and a first rack in the first transmission mechanism.
S4: executing motor torque instruction calculation in the brake boosting system;
the flow of calculation of the motor torque of the assist mechanism is shown in fig. 14, in which the control blocks of S41-S43 are shown in fig. 16. The step designs a coordination control method of the power-assisted motor and the simulation motor. The simulation motor adopts torque control and simulates the torque T of the brake pedal according to the torque required in S3 b_trg Calculating a torque instruction required by the simulation motor; the power-assisted motor adopts position closed-loop control, and gives reference torque T of the power-assisted motor according to target displacement and simulated motor torque a_FF Target position θ of brake master cylinder c_trg And the actual displacement theta c And comparing, and compensating the reference torque so as to realize stable and reliable control of the position of the brake master cylinder.
S41, calculating first torque T of the simulated motor m_cmd A second torque T corresponding to the torque of the booster motor a_FF
Referring also to FIG. 17, FIG. 17 illustrates control of the analog motor and the assist motorProcedure for simulating a first torque T of the electric machine m_cmd And (3) calculating: according to the torque T of the brake pedal b_trg And calculating the first torque T of the simulation motor according to the stress relation of the planetary gear mechanism m_cmd (ii) a Specifically, reference may be made to equation 9:
Figure GDA0003893334470000211
wherein a represents the ring gear to sun gear tooth ratio.
Calculating a second torque of the power assisting motor: simulating a first torque T of the motor according to the target pressure of the brake master cylinder m_cmd And calculating a second torque T of the power-assisted motor according to the stress relation of the planetary gear mechanism a_FF
T c_trg ＝F piston_trg ·i 2
T a_FF ＝T c_trg -(a+1)(T m_cmd +T s )
Wherein, F piston_trg For braking force of the master cylinder, i 2 The speed ratio coefficient of a second gear and a second rack in the third transmission mechanism is set; t is c_trg The torque acting on the planet carrier for the brake master cylinder;
T a_FF a second torque; t is m_cmd Is a first torque; ts is the torque of the return spring to the sun gear; a represents a gear ratio of the ring gear to the sun gear.
S42, calculating the compensation torque T according to the master cylinder reference position and the master cylinder actual position a_FB
In specific implementation, a first displacement amount (actual position) of a piston rod of a brake master cylinder is detected, a second displacement amount (target position) of the piston rod of the brake master cylinder, which needs to move, is obtained according to a braking force distribution proportion of a brake boosting system, and when the first displacement amount does not reach the second displacement amount, a boosting motor is controlled to push the piston rod to move to the second displacement amount. The part can pass through the actual position theta of the brake master cylinder c And is related to the master cylinder target position theta c_trg By comparison, a feedback compensation torque command T is output through feedback control (e.g. PID control) a_FB And realizing feedback regulation.
S43 output torque T of power assisting motor a_cmd ；
Adding the compensation torque of the power-assisted motor and the second torque to obtain the output torque T of the power-assisted motor a_cmd ：
T a_cmd ＝T a_FF +T a_FB
S44, outputting the torque of the power-assisted motor and the torque of the simulation motor;
according to the instructions calculated in S41 and S43, the output torque T of the power-assisted motor is adjusted a_cmd First torque T of analog motor m_cmd And outputting the output to a driver of the actuating motor.
In the control strategy of S4, the simulated motor torque command can be adjusted according to the pedal force desired by the driver, so that the simulation of different pedal forces can be realized; the torque of the power-assisted motor calculates a feedforward torque instruction of the power-assisted motor according to the target pressure of the brake master cylinder and the simulated motor torque instruction, and comprehensively considers the stress condition of the planetary gear mechanism on the basis of closed-loop control, so that the response speed of the planetary gear mechanism is improved, and the stable and reliable control of the position of the brake master cylinder is realized.
S5: when the power-assisted motor or the simulation motor fails, determining the third torque of the non-failed simulation motor or the non-failed power-assisted motor according to the braking force distribution proportion of the brake master cylinder, and controlling the non-failed simulation motor or the non-failed power-assisted motor to output the third torque. The reliability of the brake boosting system is improved.
As can be seen from the above description, in the braking method provided by the present application, the output torque of the analog motor and the output torque of the booster motor are simultaneously used as the force for driving the piston rod of the brake master cylinder, so that the output power requirement of a single motor can be improved. In addition, when the two motors are adopted to drive the brake master cylinder simultaneously, when one motor fails, the other motor can be used for braking, and the reliability of the whole brake power assisting system is improved.
The embodiment of the application also provides an electric automobile which comprises an automobile body, a battery arranged on the automobile body and any one of the brake power-assisted systems. In the technical scheme, the output torques of the simulation motor and the booster motor are simultaneously used as the force for driving the piston rod of the brake master cylinder, so that the output power requirement of a single motor can be improved. In addition, when the two motors are adopted to drive the brake master cylinder simultaneously, when one motor fails, the other motor can be used for braking, and the reliability of the whole brake power assisting system is improved.
The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims (19)

1. A brake boosting system applied to an electric automobile driven by a motor is characterized by comprising: the brake system comprises a brake pedal, a power-assisted motor, a simulation motor, a planet row coupling node and a brake master cylinder, wherein the brake master cylinder comprises a piston rod; the brake pedal, the power-assisted motor and the simulation motor are connected through a planet row coupling node, the planet row coupling node is used for converting the torque of the brake pedal, the torque output by the power-assisted motor and the simulation motor into acting force acting on a piston rod in the brake master cylinder, and the torque acting on the planet carrier by the brake master cylinder is the sum of the torque of the brake pedal, the torque of the power-assisted motor and the torque of the simulation motor;
the planet row coupling node includes: the device comprises a planetary gear mechanism, a first transmission mechanism, a second transmission mechanism, a third transmission mechanism and a limiting device;
the brake pedal drives the gear ring of the planetary gear mechanism to rotate through the first transmission mechanism;
the power-assisted motor drives a planet carrier of the planetary gear mechanism to rotate through the second transmission mechanism;
the simulation motor is connected with a sun gear of the planetary gear mechanism and is used for driving the sun gear to rotate;
the planet carrier pushes the piston rod to move linearly through the third transmission mechanism;
the limiting device is used for limiting the sun gear to rotate to a set angle.
2. The brake boosting system of claim 1 wherein the first transmission includes a first rack connected to the brake pedal and a first gear engaged with the first rack, wherein the first gear is fixedly connected to and coaxially disposed with the ring gear.
3. The brake boosting system of claim 2 wherein the second gear train includes a worm connected to the boost motor and a worm gear engaged with the worm and fixedly connected to and coaxially disposed with the planet carrier.
4. The brake boosting system of claim 3, wherein the third gear train includes a second rack fixedly connected to the piston rod of the master cylinder and a second gear engaged with the second rack, wherein the second gear is fixedly connected to and coaxially disposed with the carrier.
5. The brake boosting system of claim 1, 2, 3 or 4 wherein the planet row coupling node further comprises a return spring for urging the sun gear to return to an initial position.
6. The brake boosting system of claim 5, further comprising:
the first detection device is used for detecting the braking information of the electric automobile;
second detection means for detecting a battery amount of a battery of the electric vehicle;
the control device is used for acquiring the braking demand of the electric automobile according to the braking information of the electric automobile detected by the first detection device, and determining the braking force distribution ratio of the motor of the electric automobile and the brake master cylinder according to the braking demand of the electric automobile and the battery quantity of the battery of the electric automobile acquired by the second detection device; acquiring a first torque of the simulation motor according to the acquired braking information of the electric automobile; and determining a second torque of the power-assisted motor according to the first torque of the simulation motor and the braking force distribution proportion of the brake master cylinder, and controlling the power-assisted motor and the simulation motor to output the first torque and the second torque respectively.
7. The brake boosting system of claim 6 wherein the first detection device is a first displacement sensor that detects a position of the brake pedal; the control device is further configured to:
and acquiring the rotation angle of the sun gear according to the position of the brake pedal detected by the first displacement sensor and the braking force distribution proportion of the brake master cylinder, and acquiring the torque of the return spring to the sun gear according to the rotation angle of the sun gear and the elastic coefficient of the return spring.
8. The brake boosting system according to claim 7, wherein the control device is further configured to acquire the braking force of the brake pedal based on the position of the brake pedal detected by the first displacement sensor and a correspondence relationship between the position of the brake pedal and the braking force of the brake pedal;
the control device acquires a first torque of the simulation motor according to the acquired braking information of the electric automobile, and the first torque accords with the following formula:
T b_trg ＝i 1 F padel
Figure FDA0003893334460000021
wherein, T m_cmd A represents a gear ratio of the ring gear to the sun gear for the first torque; t is s Torque of the return spring to the sun gear, T b_trg Is the torque of the brake pedal, F padel As the braking force of the brake pedal, i 1 The speed ratio coefficient of a first gear and a first rack in the first transmission mechanism is shown.
9. The brake boosting system according to claim 8, wherein the control device determines the second torque of the boosting motor based on the first torque of the simulation motor and the braking force distribution ratio of the master cylinder, according to the following equation:
T c_trg ＝F piston_trg ·i 2
T a_FF ＝T c_trg -(a+1)(T m_cmd +T s )
wherein, F piston_trg Is the braking force of the master cylinder i 2 The speed ratio coefficient of a second gear and a second rack in the third transmission mechanism is obtained; t is c_trg A torque acting on the planet carrier for a brake master cylinder;
T a_FF the second torque; t is m_cmd The first torque; ts is the torque of the return spring to the sun gear; a represents a gear ratio of the ring gear to the sun gear.
10. The brake boosting system of claim 6 further comprising a second displacement sensor for detecting displacement of a piston rod of the master cylinder;
the control device is further used for acquiring the displacement of the piston rod of the brake master cylinder required to move according to the braking force distribution proportion of the brake master cylinder, and controlling the power-assisted motor to push the piston rod to move to the displacement when the second displacement sensor detects that the displacement of the piston rod does not reach the displacement.
11. The brake boosting system according to any one of claims 6 to 10, wherein the control device is further configured to determine a third torque of the non-failed dummy motor or the non-failed booster motor according to a braking force distribution ratio of the master cylinder when the booster motor or the dummy motor fails, and control the non-failed dummy motor or the non-failed booster motor to output the third torque.
12. A braking method of an electric vehicle, applied to an electric vehicle including the brake boosting system according to any one of claims 1 to 11; characterized in that the braking method comprises:
detecting braking information of the electric automobile;
acquiring a first torque of a simulation motor in the electric automobile according to the braking information of the electric automobile;
acquiring the braking requirement of the electric automobile according to the braking information of the electric automobile;
acquiring the battery capacity of a battery of the electric automobile;
determining the braking force distribution proportion of a motor and a brake master cylinder in the electric automobile according to the driving state of the electric automobile, the braking demand of the electric automobile and the battery capacity of the electric automobile;
determining a second torque of a power-assisted motor of the electric automobile according to the first torque of the simulation motor and the braking force distribution proportion of the brake master cylinder;
controlling the simulation motor to output the first torque and controlling the power-assisted motor to output the second torque;
the simulation motor and the power-assisted motor respectively output a first torque and a second torque which act on a piston rod in a brake master cylinder in the electric automobile to move.
13. The method for braking an electric vehicle according to claim 12, wherein obtaining the braking demand of the electric vehicle based on the braking information of the electric vehicle comprises:
acquiring the braking requirement of the electric automobile according to an ADAS system in the electric automobile; alternatively, the first and second electrodes may be,
and detecting the position of a brake pedal in the electric automobile, and acquiring the braking demand of the electric automobile according to the position of the brake pedal and the set corresponding relation between the position of the brake pedal and the braking demand.
14. The braking method of an electric vehicle according to claim 13, further comprising:
acquiring the braking force of the brake pedal according to the position of the brake pedal and the set corresponding relation between the position of the brake pedal and the braking force of the brake pedal;
acquiring a rotation angle of a sun gear in the electric automobile according to the position of the brake pedal and the braking force distribution proportion of the brake master cylinder, and acquiring torque of a return spring on the sun gear according to the rotation angle of the sun gear and the elastic coefficient of the return spring in the electric automobile;
the sun gear is positioned in a planetary gear mechanism of a planetary line coupling node in the electric automobile, and the planetary line coupling node is used for converting the braking force of the brake pedal, the torque of the return spring on the sun gear, and first and second torques respectively output by the power-assisted motor and the simulation motor into acting force acting on a piston rod in the brake master cylinder.
15. The braking method of an electric vehicle according to claim 14, wherein the first torque of the simulated motor is obtained according to the braking information of the electric vehicle, according to the following formula:
T b_trg ＝i 1 F padel
Figure FDA0003893334460000041
wherein, T m_cmd Is the first torqueA represents a gear ratio of the ring gear to the sun gear; t is s Torque of the return spring to the sun gear, T b_trg Is the torque of the brake pedal, F padel As the braking force of the brake pedal, i 1 The speed ratio coefficient of a first gear and a first rack in the first transmission mechanism is obtained;
the gear ring and the first transmission mechanism are arranged in the planet row coupling node, the first rack is connected with the brake pedal, the first gear is meshed with the first rack, and the first gear is fixedly connected with the gear ring and coaxially arranged.
16. The braking method of an electric vehicle according to claim 15, wherein the second torque of the booster motor is determined according to the first torque of the simulation motor and the braking force distribution ratio of the brake master cylinder, and the following formula is satisfied:
T c_trg ＝F piston_trg ·i 2
T a_FF ＝T c_trg -(a+1)(T m_cmd +T s )
wherein, F piston_trg Is the braking force of the master cylinder i 2 The speed ratio coefficient of a second gear and a second rack in the third transmission mechanism is obtained; t is c_trg The torque acting on the planet carrier for the brake master cylinder;
T a_FF the second torque; t is m_cmd The first torque; ts is the torque of the return spring to the sun gear; a represents a gear ratio of the ring gear to the sun gear;
the first transmission mechanism and the planet carrier are arranged in the planet row coupling node, the second rack is fixedly connected with a piston rod of the brake master cylinder, the second rack is meshed with the second gear, and the second gear is fixedly connected with the planet carrier and coaxially arranged.
17. The braking method of an electric vehicle according to claim 12, further comprising:
detecting a first displacement amount of a piston rod of the brake master cylinder;
and according to the braking force distribution proportion of the brake boosting system, acquiring a second displacement amount of the piston rod of the brake master cylinder, which needs to move, and controlling the boosting motor to push the piston rod to move to the second displacement amount when the first displacement amount does not reach the second displacement amount.
18. The braking method of an electric vehicle according to any one of claims 12 to 17, further comprising:
and when the power-assisted motor or the simulation motor fails, determining a third torque of the non-failed simulation motor or the non-failed power-assisted motor according to the braking force distribution proportion of the brake master cylinder, and controlling the non-failed simulation motor or the non-failed power-assisted motor to output the third torque.
19. An electric vehicle characterized by comprising a vehicle body, a battery provided on the vehicle body, and the brake boosting system according to any one of claims 1 to 11.
CN201910581690.7A 2019-06-30 2019-06-30 Brake boosting system, brake method and electric automobile Active CN112224190B (en)

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BR112021010535A BR112021010535A2 (en) 2019-06-30 2020-03-17 Brake assist system, braking method and electric vehicle
MX2021006676A MX2021006676A (en) 2019-06-30 2020-03-17 Brake boosting system, braking method and electric vehicle.
KR1020217013822A KR102585991B1 (en) 2019-06-30 2020-03-17 Brake boosting systems, braking methods and electric vehicles
PCT/CN2020/079771 WO2021000601A1 (en) 2019-06-30 2020-03-17 Brake boosting system, braking method and electric vehicle
EP20834110.7A EP3851348A4 (en) 2019-06-30 2020-03-17 Brake boosting system, braking method and electric vehicle
JP2021527947A JP7187695B2 (en) 2019-06-30 2020-03-17 Braking Assist Systems, Braking Methods, and Electric Vehicles
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Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20210142793A (en) * 2020-05-18 2021-11-26 현대자동차주식회사 Electric braking booster for autonomous driving vehicle composed of dual actuator
CN113978440A (en) * 2021-09-24 2022-01-28 合众新能源汽车有限公司 Novel brake backup method and system
CN113734114B (en) * 2021-11-03 2022-09-02 杭州夏树科技有限公司 Auxiliary emergency braking device for electric automobile
CN113928288B (en) * 2021-11-25 2023-04-11 中国科学院电工研究所 Braking system with double independent braking units and braking method
CN114194152B (en) * 2021-11-29 2024-04-16 帷幄汽车咨询(南京)有限公司 New energy electric automobile safety braking device
CN115123167A (en) * 2022-06-08 2022-09-30 燕山大学 Direct-drive brake-by-wire device for redundant motor of automatic driving automobile and control method
CN115384469B (en) * 2022-08-24 2024-01-09 西安主函数智能科技有限公司 Dynamic torque distribution method based on air brake and electric brake of new energy engineering vehicle

Family Cites Families (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4395883A (en) * 1980-12-22 1983-08-02 General Motors Corporation Electric brake booster
US5706918A (en) * 1995-12-26 1998-01-13 General Motors Corporation Brake apply mechanism
US6554088B2 (en) * 1998-09-14 2003-04-29 Paice Corporation Hybrid vehicles
JP2005112025A (en) * 2003-10-03 2005-04-28 Hitachi Unisia Automotive Ltd Steering control device
JP5003205B2 (en) * 2007-02-27 2012-08-15 株式会社アドヴィックス Brake control device for vehicle
US8069662B1 (en) * 2008-10-30 2011-12-06 Robert Bosch Gmbh Eccentric cam brake booster
DE102009028034A1 (en) * 2009-07-27 2011-02-03 Robert Bosch Gmbh Hydraulic master cylinder
JP2011093472A (en) * 2009-10-30 2011-05-12 Hitachi Automotive Systems Ltd Electric booster
CN103754206B (en) 2014-01-08 2016-08-17 同济大学 A kind of mechano-electronic brake fluid system
CN103754209A (en) * 2014-01-08 2014-04-30 同济大学 Electronic hydraulic braking system
CN103754208B (en) 2014-01-08 2016-06-22 同济大学 A kind of EHB of Dual-motors Driving
JP6252519B2 (en) * 2015-03-06 2017-12-27 トヨタ自動車株式会社 Control device for hybrid vehicle
CN104709096B (en) 2015-03-27 2017-03-01 吉林大学 There is the electric booster braking system of frictional damping and the full decoupled function of regenerative braking
CN204567642U (en) * 2015-03-31 2015-08-19 同济大学 A kind of differential cooperative type dual power source EHB
US9925968B2 (en) * 2015-05-18 2018-03-27 Beijingwest Industries Co., Ltd. Brake booster assembly
CN105857283B (en) * 2015-05-18 2018-09-25 北京京西重工有限公司 Brake boost device assembly
CN106585602B (en) * 2015-10-20 2019-08-30 上海汇众汽车制造有限公司 Bi-motor electromechanical braking servomechanism
CN105667485B (en) * 2016-01-11 2018-01-23 清华大学 A kind of energy assisted braking system for automobile
CN107757591B (en) * 2016-08-23 2020-05-22 上汽通用汽车有限公司 Electronic control brake power assisting system and vehicle brake system
US10137876B2 (en) * 2016-09-30 2018-11-27 Advics Co., Ltd. Braking control device for vehicle
KR20180094589A (en) * 2017-02-16 2018-08-24 주식회사 만도 Gear assembly and brake apparatus using thereof
CN206598841U (en) * 2017-03-16 2017-10-31 南京奥特博机电科技有限公司 Vehicle composite braking system and vehicle
CN107031597B (en) 2017-04-18 2023-12-29 上海同驭汽车科技有限公司 Integrated electronic hydraulic braking system and method
CN107226076B (en) * 2017-05-17 2020-02-14 江苏理工学院 Brake feel simulation device based on motor force
CN108482346A (en) * 2018-05-24 2018-09-04 吉林大学 A kind of brake power recovering device and its control method

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